Results: Regression analysis showed that young age (15–24 years), ethnicity (with a gradient of risk black >white >Asian), and residence
in inner city areas of deprivation were independent risk factors for all STDs. There were highly significant correlations
in the geospatial distribution of incidence rates between the four infections. However, there was variation in the degree
of central urban clustering, with gonorrhoea having the most restricted, and genital warts and chlamydia the widest distribution.
31% of all disease occurred in the four inner city census wards, representing 15% of the population.

Conclusion: These results are in keeping with core group theory applying in a unified manner to the four most common UK sexually transmitted
diseases in this urban area. Population based studies are needed to clarify whether ethnicity is associated with differing
sexual behavioural or mixing patterns. Our data suggest that chlamydia screening in women <25 years of age could detect 70%
of cases in the community, that such programmes should give particular emphasis to implementation in core group areas, and
that they could function as unifying strategies for the control of most common STDs within urban areas.